1. Field of Art
The present disclosure relates to depositing one or more layers of materials on a substrate using vapor phase deposition.
2. Description of the Related Art
An atomic layer deposition (ALD) is a thin film deposition technique for depositing one or more layers of material on a substrate. ALD uses two types of chemical, one is a source precursor and the other is a reactant precursor. Generally, ALD includes four stages: (i) injection of a source precursor, (ii) removal of a physical adsorption layer of the source precursor, (iii) injection of a reactant precursor, and (iv) removal of a physical adsorption layer of the reactant precursor. ALD can be a slow process that can take an extended amount of time or many repetitions before a layer of desired thickness can be obtained. Hence, to expedite the process, a vapor deposition reactor with a unit module (so-called a linear injector), as described in U.S. Patent Application Publication No. 2009/0165715 or other similar devices may be used to expedite ALD process. The unit module may include an injection unit and an exhaust unit for a source material (collectively a source module), and an injection unit and an exhaust unit for a reactant (collectively a reactant module). To deposit different films or laminates onto the substrate, different source precursors and/or reactant precursors can be injected into different modules.
A spatial ALD vapor deposition chamber has one or more sets of reactors for performing spatial ALD on substrates. Spatial ALD refers to a process where source precursor, purge gas, reactant precursor and purge gas are sequentially injected onto a moving substrate to form a layer of film thereon. As the substrate passes below the reactors, the substrate is exposed to the source precursor, a purge gas and the reactant precursor. The source precursor molecules deposited on the substrate reacts with reactant precursor molecules or the source precursor molecules are replaced with the reactant precursor molecules to deposit a layer of material on the substrate. After exposing the entire substrate to the source precursor or the reactant precursor, the substrate may be exposed to the purge gas to remove excess source precursor molecules or reactant precursor molecules from the substrate.
The substrate and the reactors may be moved by a reciprocating movement where the substrate is exposed to the precursor molecules in a different sequence during a forward stroke and a backward stroke. In order to expose the entire substrate to the precursor molecules or purge gas, the substrate or the reactor may have to travel a long distance. Hence, the vapor deposition reactor may be very large to accommodate the reciprocal movement of the substrate or the reactor.